Oil leaking out of e.g. a high pressure conduit for the supply of fuel in a vessel is hazardous due to the risk of fire and/or explosion. Moreover, if an oil leakage in an engine room is discovered late, the leaked oil will cover all surfaces in the engine room and leave an immense cleaning task for the crew. For these reasons it is desirable to detect an oil leakage as early as possible.
Various oil leakage detectors are known from the prior art. Most commercially available detectors rely either on a gas sensor for detecting the presence of e.g. carbon dioxide in air or on an optical system, in which light reflected from oil particles or droplets is detected. Systems relying solely on gas sensors have been found to be unreliable in many instances. Whereas systems relying on optics and light for detecting the presence of oil have become popular, they suffer from the drawback that they react too slowly in case an oil leakage produces relatively large droplets of oil, as they do not emit a warning signal until the density of oil exceeds the acceptable threshold value by far. This is believed to be due to the fact that large oil particles or droplets provide a relatively small reflection per unit weight in comparison to smaller particles, which provide a higher reflection per unit weight. Accordingly, there is a need for an oil leakage detector which is reliable, and which emits the appropriate warning signal even in the case of large oil particles or droplets.